Quote Originally Posted by jrw View Post
Any idea as to cause of horizontal pattern from the grids? Not something I recall seeing before when working with grids.
No idea, just an observation. Maybe someting to do with the head design of the 600EX-RT? I don't see it with the 8.5" grids I use on my Einstein. I did follow Honl's suggestion of putting the Speed Strap on the flash head with ~1/2" protrusion from the head, so when the grid is attached, there's some space for cooling. I actually didn't try varying that gap, but I might.